Ultra-soft water, radon spring water, and auto löyly lead you to an exceptional state of perfect relaxation
Tokyo Nakano City
"Natural Hot Spring Takarayu" is an evolved public bath in Wakamiya, Nakano City, Tokyo, which was certified as a natural hot spring in 2025. It uses high-quality groundwater that bubbles up from underground, further refined into highly purified ultra-soft water. The sauna area offers two types that change monthly: a stone sauna equipped with auto löyly for powerful heat, and a comfort sauna with just the right level of humidity. The cold plunge bath, a radon spring water bath passed through highly concentrated Bad Gastein ore, the first of its kind at a bathing facility, has an amazingly smooth feel on the skin. With outdoor silky baths, carbonated spring baths, and more, this carefully crafted healing space offers attention to detail in every corner.
TypeNatural Hot Spring
A natural hot spring certified in 2025. Its signature feature is radon spring water using Bad Gastein ore, which helps soothe both body and mind together with the negative ions that fill the bath area. The ultra-softened water is exceptionally gentle on the skin, and its moist, lingering feeling after bathing continues for a long time.
Sauna TypeDry Sauna
Stove TypeConvection Stove (Sauna Stone)
Capacity10people
An authentic Finnish-style sauna that heats sauna stones. Regularly performed auto löyly helps maintain the room's temperature and humidity at an ideal balance, encouraging a high-quality sweat. Wrapped in the warmth of wood, it is a space where you can slowly and deeply face the heat.
Water QualitySoft Water
Capacity4people
A cold plunge bath of ultra-soft radon spring water that has passed through highly concentrated Bad Gastein ore. It offers a crisp chill, yet the water feels astonishingly smooth and has a skin-clinging texture. In a space full of negative ions, it gently leads you into a deep state of relaxation.
Closed Days: Monday
1-49-1 Wakamiya, Nakano City, Tokyo 165-0033
Gender Access
Gender Separated
Curated by an expert who visits onsen and sauna facilities every day and has explored 300+ locations — only facilities confirmed to be truly exceptional are featured.
Learn more
Ultra-soft water, radon spring water, and auto löyly lead you to an exceptional state of perfect relaxation
Tokyo Nakano City
"Natural Hot Spring Takarayu" is an evolved public bath in Wakamiya, Nakano City, Tokyo, which was certified as a natural hot spring in 2025. It uses high-quality groundwater that bubbles up from underground, further refined into highly purified ultra-soft water. The sauna area offers two types that change monthly: a stone sauna equipped with auto löyly for powerful heat, and a comfort sauna with just the right level of humidity. The cold plunge bath, a radon spring water bath passed through highly concentrated Bad Gastein ore, the first of its kind at a bathing facility, has an amazingly smooth feel on the skin. With outdoor silky baths, carbonated spring baths, and more, this carefully crafted healing space offers attention to detail in every corner.
TypeNatural Hot Spring
A natural hot spring certified in 2025. Its signature feature is radon spring water using Bad Gastein ore, which helps soothe both body and mind together with the negative ions that fill the bath area. The ultra-softened water is exceptionally gentle on the skin, and its moist, lingering feeling after bathing continues for a long time.
Sauna TypeDry Sauna
Stove TypeConvection Stove (Sauna Stone)
Capacity10people
An authentic Finnish-style sauna that heats sauna stones. Regularly performed auto löyly helps maintain the room's temperature and humidity at an ideal balance, encouraging a high-quality sweat. Wrapped in the warmth of wood, it is a space where you can slowly and deeply face the heat.
Water QualitySoft Water
Capacity4people
A cold plunge bath of ultra-soft radon spring water that has passed through highly concentrated Bad Gastein ore. It offers a crisp chill, yet the water feels astonishingly smooth and has a skin-clinging texture. In a space full of negative ions, it gently leads you into a deep state of relaxation.
Closed Days: Monday
1-49-1 Wakamiya, Nakano City, Tokyo 165-0033
Gender Access
Gender Separated
Curated by an expert who visits onsen and sauna facilities every day and has explored 300+ locations — only facilities confirmed to be truly exceptional are featured.
Learn more